Cisco CCNA / CCNP Certification Test: Troubleshooting Direct Serial Connections
A primary subject matter of your respective CCNA and CCNP CIT tests are going 인스타 팔로워 구매 to be connecting Cisco routers instantly via their Serial interfaces, and whilst the configuration is simple, there are many very important specifics and exhibit instructions you should know in order to move the examinations and configure this properly in output and home lab networks. Permit’s Have a look at a sample configuration.
Connecting Cisco routers straight via their Serial interfaces performs very well as soon as you get it operating – and obtaining this kind of connection up and working is simple more than enough. You may use clearly show controller serial x to understand which endpoint is acting as the DCE, and it’s the http://www.bbc.co.uk/search?q=인스타 팔로워 구매 DCE that need to be configured Together with the clockrate command.
R3#display controller serial one
HD device one, idb = 0x11B4DC, driver structure at 0x121868
buffer sizing 1524 HD unit 1, V.35 DCE cable
R3(config)#int serial1
R3(config-if)#ip deal with 172.twelve.13.three 255.255.255.0
R3(config-if)#clockrate 56000
R3(config-if)#no shut
Failure to configure the clockrate has some fascinating outcomes concerning the Bodily and rational condition of your interfaces. Allow’s clear away the clockrate from R3 and find out what comes about.
R3(config)#int s1
R3(config-if)#no clockrate 56000
R3(config-if)#
18:02:19: %LINEPROTO-five-UPDOWN: Line protocol on Interface Serial1, adjusted state to down
The line protocol doesn’t fall right away, but it does drop. Allow’s operate show interface serial1 to compare the Bodily and rational interface states.
R3#exhibit int serial1
Serial1 is up, line protocol is down
Bodily, the interface is ok, Hence the Bodily interface is up. It’s just the logical Element of the interface – the road protocol – which is down. It’s exactly the same predicament on R1.
R1#exhibit inter serial1
Whilst a router misconfiguration could be the most probably cause of a serial connection issue, that’s not the sole cause of clocking problems. Cisco’s Web site documentation mentions CSU/DSU misconfiguration, out-of-spec cables, terrible patch panel connections, and connecting a lot of cables alongside one another as other good reasons for clocking challenges. Even now, the number 1 cause of clocking difficulties in my working experience is simply forgetting to configure the clockrate command!